Debut: Comic #13
Ridley's backstory is pretty much unknown, though there are conflicts if whether Ridley is the true leader of the Space Pirates or if Mother Brain is the true leader of the Pirates in the Metroid universe. Regardless, Ridley is the one responsible for the deaths of Samus Aran's parents on the space colony of K-2L.
In Metroid: Third Dervivative, it's revealed that Ridley's return was through cloning even though Samus had defeated him twice previously.
When we first see Ridley, he is en route to Nemesis via Pirate vessel. As of his latest appearance, he is still en route to Nemesis via Pirate vessel. The implication is that Nemesis is not particularly close to known Space Pirate territory.
His first few appearances are largely filler, as he deals with the boredom of the long commute and receives information on the Hunter's presence. In order, he:
- Gets cold chills on two occasions, which happen to coincide with times when Mother Brain reveals her affection for him
- Upon learning that Joey has betrayed the Space Pirates, creates and slaughters multiple Joey clones to work off his stress
- Attacks his navigators for taking so long to reach Nemesis
- Contacts JD and demands a progress report for one of his projects
- Complains about the boredom of space, which may or may not be attributable to Mother Brain's influence
Eventually, he is the focus of several consecutive comics. In this sequence, he institutes a short-lived exercise program on his vessel, fools around with the DNA of several human hostages his vessel was carrying, and starts an impromptu deathmatch between two of his combat troopers. He also checks in on JD again, although he may be slightly too late to notice that Samus has been in JD's lab recently.
Ridley's abilities have changed over time, but he's mainly known for his trademark fireball, flamethrower, flying, and melee attacks (including attacking with his tail).
As powerful as Ridley is, he is very vulnerable to ballistic weaponry. If the Space Pirates ever figure out how to shield Ridley against ballistics, Ridley could become unstoppable in the Space Pirate forces.
One of the main reasons why Ridley is assigned to leadership and combat positions may be his natural tendency to instigate violence. It's completely believable. Ridley is vicious, quick to rile, and has no compunction against slaughtering his underlings if they displease him. Even his leisure activities seem to involve violence in one way or another.
At the same time, he commands a lot of respect and adoration among the Space Pirates in addition to fear. There may be more to his personality than we've seen, or perhaps the Space Pirates merely agree with his ideologies. Perhaps future appearances in the comic may reveal additional details and aspects of his personality.